Web-based commercial transactions are an important part of e-commerce business activities. There are increasing demands placed on computer applications to integrate the various applications used by businesses in connection with their back office systems. With increases in the amount of web-based transactions and other related activities, there are increased demands for synchronized integration of those various applications.
As the nature and extent of e-commerce activities has evolved, there has been an increased need for integration between Web-based applications and back office back-end systems (including ERP—Enterprise Resource Planning systems). The synchronized transfer of information between the two systems (i.e., in proper time sequence) is an important aspect of system integration. The messages transferred between the two systems must be processed in a manner ensuring that the information contained in those messages is modified or altered in the appropriate time sequence. If the transferred messages are not processed in the proper time sequence, certain important aspects of the transferred information may be lost or incorrectly processed.
In establishing the integration between the two systems, one of the possible approaches is to use messages that are passed back and forth between the Web-based application and the back office system.
It is important that the web-based application have the ability to suitably process inbound messages coming from the back office systems. The types of inbound messages can vary depending on the business needs of the particular business enterprises that are being considered. Some examples of the kinds of inbound messages frequently encountered in a Web-based application are:
Order Confirmation;
Order Delivery;
Order Invoice;
Product Inventory Updates;
Product Price Updates; and
Customer Information Updates.
There are of course, many other types of messages encountered in e-commerce related activities.
If a message queue system is used in transmitting messages between a back office system and one or more network systems, synchronization problems often develop. That is, often, the flow of the messages between the back office and web-based systems becomes asynchronous. The asynchronous messages are often sent and received out of sequence despite their respective times of creation.
One of the issues resulting from asynchronous methods of communication is the unpredictable time of arrival of incoming messages. The unpredictability of these arrival times may in turn lead to unpredictable queuing of incoming messages. There may be undesirable changes to the expected or desired order or sequencing of inbound messages waiting in the queue for processing by the web-based application. Problems may arise in circumstances in which incoming messages are received out of their intended or expected order.
The problem of asynchronous messages may be caused by many different reasons, including for example:                A document containing important commercial information, (for example, an Order Invoice, Customer Information, or other document), may be updated several times within a relatively short time interval by the back-office systems. Each updated version of the message or revision will typically generate new inbound messages to the Web.        In a complex communication environment, the revised messages may travel through different data network routes and arrive at the intended destinations at unpredictable times.        To boost performance, multiple inbound queue server processes may be used.        The back office system may send out the messages from multiple ports.        Multi-threaded processing of inbound messages by the Web-based application.        
The problem of asynchronous messages may cause more recent data to be overwritten by older data, creating inconsistencies between the Web-based application and the back office system. The web-based application may process incoming messages out of their intended order, resulting in a variety of potentially serious errors in the web-based system.